First picture of the boy who won heart of Anne Frank

It was the dark hair, the 'velvety' brown eyes and the ever so slightly pointed nose that she admired. But above all it was his smile that she was 'crazy about'.

More than 60 years after he stole her heart, The Observer today publishes for the first time a photograph of Peter Schiff - the handsome schoolboy whom Anne Frank one day hoped to marry.

Frank, the bright Jewish schoolgirl immortalised in the famous diary she wrote while in hiding from the Nazis in Amsterdam during the Second World War, was captivated by Schiff. Three years her senior, she met him at school in 1940, his family having fled from Berlin to Holland the previous year.

Though only 11, she fell in love, and it was, in part, the passion she felt for him that sustained her throughout the two years that she and her family would spend confined in a secret annexe in the Dutch city.

In her diary - which became a publishing sensation after her death and has sold more than 31 million copies worldwide - she wrote of their first summer together when they were 'inseparable', walking hand-in-hand through their neighbourhood. She also described the painful, palpable dream she had of him, and of times when she awoke believing she could feel his cheek against hers.

She described, too, the adolescent angst she felt over the possibility of losing him. Recalling how they grew apart, she wrote on 7 January, 1944: 'I'd gone to the country during the summer holidays, and when I came back Peter was no longer at his old address; he'd moved and was living with a much older boy, who apparently told him I was just a child, because Peter stopped seeing me. I loved him so much that I didn't want to face the truth. I kept clinging to him until the day I finally realised that if I continued to chase after him, people would say I was mad about boys.'

Her last mention of Schiff, whom she called Petel, was at the end of April 1944, six weeks before her 15th birthday and three months before their safe house was raided by the German security police. After another passionate and intense dream, she wrote: 'I love Peter as I have never loved anyone.'

Upon capture, Frank would be taken to Auschwitz, then to Bergen-Belsen where, just weeks before liberation, she died of typhus.

Until now Schiff has been a faceless footnote at the bottom of this most emotional chapter of modern history. He might have remained forever unknown but for a series of extraordinary coincidences revealed by the writer Simon Garfield in today's Observer Magazine

The compelling story of how this picture was finally unearthed spans 70 years. It is rooted in a schoolboy friendship back in Berlin in the summer of 1939, amid the horrifying fallout of the Kristallnacht pogrom against Jews and before Schiff's family fled to Amsterdam.

It concludes in north London, where an 81-year-old widower's fractured, yet still vivid, memories set him on an inexorable quest to prove his old schoolboy friend was the same boy who would later win Frank's youthful heart.

Before Schiff left Berlin for the Netherlands, he said goodbye to his close schoolfriend Ernst 'Mic' Michaelis, who was being sent to England on the Kindertransport. As awkward 12-year-olds not knowing what futures they faced, nor how to bid each other farewell, they exchanged photographs.

Schiff wrote a note: 'In friendly remembrance of your friend Lutz Peter Schiff', using his full name. Michaelis pasted both note and photograph - which is a standard passport size - into an album. A few years later he transferred it to a larger album, and there it remained - for decades.

Today Michaelis, a director of Pearson Panke, an automotive and aerospace machinery supplier, recalls how on first reading Frank's diary in the Fifties he idly wondered whether his friend Schiff could be the Peter of whom she wrote.

Fifty years later his wife, after being diagnosed with terminal cancer, bought a new copy of the journal. Last year he re-read it after her death and became convinced his Peter was indeed Frank's.

'I realised there were a lot of pictures associated with her life, but no picture of Peter Schiff,' he tells Garfield. 'That seemed very odd, as his looks are at the heart of his story.' It has taken time, extraordinary effort, internet research and a series of happy coincidences for Michaelis to get authentication that his picture is that of the Schiff whom Frank so adored. It will now go on display on the Anne Frank House website.

'He is a beautiful boy,' said Garfield. 'It's just a passport-type picture, but it has never been seen outside of "Mic's" album. You can see why any girl of any age would fall for someone like that.'

And what of Schiff's fate? Records show he, too, was captured and died, either in Auschwitz or Bergen-Belsen. The date of his death remains unknown - as his smile would have done had it not been for 'Mic' and the part he has

Anne Frank's life

· Annelies Marie 'Anne' Frank was born into a Jewish family in Frankfurt in 1929. The family moved to Amsterdam in 1933 to escape the Nazis.

· Following the fall of the Netherlands, she went into hiding with her family and four friends in July 1942. They spent two years in secret rooms behind her father's office building.

· For her 13th birthday, she was given a diary in which she chronicled her life until August 1944, when the family was betrayed and deported. Anne died of typhus in Bergen-Belsen concentration camp in the spring of 1945.

· The Diary of a Young Girl was published in 1947 by her father, Otto, who survived the Holocaust.